Abstract: An improved power amplifier having complimentary power transistors connected in push-pull arrangement, and having a bias voltage source coupled to the transistors for generating a transverse idling current flowing through the complimentary pair of transistors. A regulating, feedback control circuit has a set point input and inputs connected to precision resistors connected to detect the current through the power transistors and the output current. Analog arithmetic computing circuits continuously compute the instantaneous difference between the detected transverse idling current through the power transistors and the set point input for the idling current. The output of the controller circuit is connected to the bias voltage sources to vary the bias voltage in proportion to the instantaneous difference between the detected transverse idling current and the set value of idling current to maintain a constant, transverse idling current.